Okay, could someone please explain this to me like I am a four-year-old.

As far as I got from the Linux Action Show guys, Ubuntu Touch currently runs on the Android kernel and uses the Android graphical environment (or what is the proper term for this? It can't be windows manager since Android doesn't have windows). In any case, Ubuntu Touch doesn't have X11, so normal desktop apps will not run on it. Which improves compatibility with Android devices, but greatly reduces its appeal.

(Some will argue that we do not need desktop apps on a touch device anyway. I don't know. I guess I could use them on a 10-inch tablet.)

Now here is the part that I don't understand. The ad for Ubuntu Touch showed a concept of a single OS that could work on one and the same device depending on whether the device is docked and connected to a monitor or a TV screen. Presimably, the idea is once you dock your device you get the normal desktop Ubuntu with all the goodness of LibreOffice and GIMP and such like. We already have something like this in Ubuntu for Android.

So here is my question. If a phone could transform into a desktop once it is docked, do you think it will be possible to switch between the interfaces in the tablet. In other words, are there any technological limitations that prevent switching from Ubuntu Touch to Ubuntu desktop on a tablet without docking it?